Nissan Murano Z50 (2003 year). Manual

TROUBLE DIAGNOSIS

ATC-75

ATC

Revision; 2004 April

2003 Murano

AUXILIARY MECHANISM: FOOT POSITION SETTING TRIMMER

Wind distribution ratio in FOOT mode can be set.

Operating procedures for this trimmer are as follows:

●

Begin Self-diagnosis STEP-5 mode. Refer to

ATC-68, "Self-diagnosis Function"

●

Turn fan control dial clockwise to set system in auxiliary mode.

●

Display shows 61 in auxiliary mechanism. It takes approximately 3 seconds.

●

Press the mode switch as desired.

AUXILIARY MECHANISM: INLET PORT MEMORY FUNCTION

When ignition key is turned from OFF to ON, inlet port can be set to AUTO or manual.

Operating procedures for this trimmer are as follows:

●

Begin Self-diagnosis STEP-5 mode. Refer to

ATC-68, "Self-diagnosis Function"

●

Turn fan control dial clockwise to set system in auxiliary mode.

●

Display shows 61 in auxiliary mechanism. It takes approximately 3 seconds.

●

Press the recirculation (REC) and fresh (FRE) switch as desired.

RJIA1764E

Switch

LED status of

REC/FRE

switch

Setting status

Setting changeover method

REC

Manual REC status is memorized. (Initial setting)

REC SW: ON

OFF

AUTO control

FRE

Manual FRE status is memorized.

FRE SW: ON

OFF

AUTO control (Initial setting)

ATC-76

TROUBLE DIAGNOSIS

Revision; 2004 April

2003 Murano

Operational Check

AJS000Z4

The purpose of the operational check is to confirm that the system operates properly.

CHECKING MEMORY FUNCTION

Set the temperature to 32

C (90

F).

Press OFF switch.

Turn ignition switch OFF.

Turn ignition switch ON.

Press the AUTO switch.

Confirm that the set temperature remains at previous tempera-
ture.

Press OFF switch.

If NG, go to trouble diagnosis procedure for

ATC-114, "Memory

Function"

If OK, continue with next check.

CHECKING BLOWER

Turn fan control dial clockwise. Blower should operate on low
speed. The fan symbol should have one blade lit.

Turn fan control dial clockwise again, and continue checking
blower speed and fan symbol until all speeds are checked.

Leave blower on MAX speed.

If NG, go to trouble diagnosis procedure for

ATC-95, "DIAGNOSTIC

PROCEDURE FOR BLOWER MOTOR"

If OK, continue with next check.

CHECKING DISCHARGE AIR

Press MODE switch and DEF switch.

Each position indicator should change shape.

Confirm that discharge air comes out according to the air distri-
bution table. Refer to

ATC-31, "Discharge Air Flow"

If NG, go to trouble diagnosis procedure for

ATC-84, "Mode Door

Motor Circuit"

If OK, continue with next check.

NOTE:
Confirm that the compressor clutch is engaged (sound or visual
inspection) and intake door position is at FRESH when the DEF or
D/F is selected.

Conditions

: Engine running and at usual operating temperature

RJIA1765E

RJIA1766E

RJIA1767E

RJIA1761E

TROUBLE DIAGNOSIS

ATC-77

ATC

Revision; 2004 April

2003 Murano

CHECKING RECIRCULATION

Press recirculation (REC) switch one time. Recirculation indica-
tor should illuminate.

Press fresh (FRE) switch one time. Fresh indicator should illumi-
nate.

Listen for intake door position change (you should hear blower
sound change slightly).

If NG, go to trouble diagnosis procedure for

ATC-90, "Intake Door

Motor Circuit"

If OK, continue with next check.

NOTE:
Confirm that the compressor clutch is engaged (sound or visual
inspection) and intake door position is at FRESH when the DEF or D/F is selected.

CHECKING TEMPERATURE DECREASE

Turn temperature dial (driver side) counterclockwise until 18

(60

F) is displayed.

Check for cold air at discharge air outlets.

If NG, go to trouble diagnosis procedure for

ATC-104, "Insufficient

Cooling"

If OK, continue with next check.

CHECKING TEMPERATURE INCREASE

Turn temperature dial (driver side) clockwise until 32

C (90

F) is

displayed.

Check for hot air at discharge air outlets.

If NG, go to trouble diagnosis procedure for

ATC-111, "Insufficient

Heating"

If OK, continue with next check.

CHECK A/C SWITCH

Press AUTO switch and A/C switch.

A/C switch indicator will turn ON.

●

Confirm that the compressor clutch engages (sound or visual
inspection).

If NG, go to trouble diagnosis procedure for

ATC-98, "Magnet Clutch

Circuit"

If OK, continue with next check.

RJIA1768E

RJIA1769E

RJIA1770E

RJIA2099E

ATC-78

TROUBLE DIAGNOSIS

Revision; 2004 April

2003 Murano

CHECKING AUTO MODE

Press AUTO switch and A/C switch.

Display should indicate AUTO.

●

Confirm that the compressor clutch engages (sound or visual
inspection). (Discharge air and blower speed will depend on
ambient, in-vehicle, and set temperatures.)

If NG, go to trouble diagnosis procedure for

ATC-78, "Power Supply

and Ground Circuit for Auto Amp."

, then if necessary, trouble diag-

nosis procedure for

ATC-98, "Magnet Clutch Circuit"

If all operational checks are OK (symptom cannot be duplicated), go
to malfunction Simulation Tests in

GI-26, "How to Perform Efficient

Diagnosis for an Electrical Incident"

and perform tests as outlined to

simulate driving conditions environment. If symptom appears, refer
to

ATC-57, "SYMPTOM TABLE"

and perform applicable trouble diagnosis procedures.

Power Supply and Ground Circuit for Auto Amp.

AJS000Z5

SYMPTOM: A/C system does not come on.

INSPECTION FLOW

RJIA1771E

ATC-78, "Power Supply and Ground
Circuit for Auto Amp."

ATC-76, "Operational Check"

AV-103, "Trouble Diagnosis Chart by
Symptom"

AV-219, "A/C Does Not Work"

RJIA1772E

TROUBLE DIAGNOSIS

ATC-79

ATC

Revision; 2004 April

2003 Murano

COMPONENT DESCRIPTION
Unified meter and A/C amp. (Automatic Amplifier)

The unified meter and A/C amp. has a built-in microcomputer which
processes information sent from various sensors needed for air con-
ditioner operation. The air mix door motor, mode door motor, intake
door motor, blower motor and compressor are then controlled.
The unified meter and A/C amp. is unitized with control mechanisms.
When the various switches and temperature dials are operated, data
is input to the unified meter and A/C amp. from the DISPLAY UNIT/
DISPLAY CONTROL UNIT using CAN communication.
Self-diagnostic functions are also built into unified meter and A/C
amp. to provide quick check of malfunctions in the auto air condi-
tioner system.

Potentio Temperature Control (PTC)

The PTC is built into the A/C and AV switch. It can be set at an inter-
val of 0.5

C (1.0

F) in the 18

C (60

F) to 32

C (90

F) temperature

range by turning temperature dial. The set temperature is displayed.

DIAGNOSTIC PROCEDURE FOR A/C SYSTEM

SYMPTOM: A/C system does not come on.

RJIA1758E

RJIA1773E

SJIA0301E

ATC-80

TROUBLE DIAGNOSIS

Revision; 2004 April

2003 Murano

CHECK POWER SUPPLY CIRCUIT FOR UNIFIED METER AND A/C AMP.

Disconnect unified meter and A/C amp. connector.

Check voltage between unified meter and A/C amp. harness
connector M50 terminals 21 (Y/R), 22 (G) and 35 (P/B), unified
meter and A/C amp. harness connector M51 terminal 46 (W/L)
and ground.

OK or NG

>> GO TO 2.

>> Check 10A and 15A fuses [Nos. 6, 10, 11, 12 and 19, located in the fuse block (J/B)]. Refer to

PG-

87, "FUSE BLOCK - JUNCTION BOX (J/B)"

●

If fuses are OK, check harness for open circuit. Repair or replace as necessary.

●

If fuses are NG, replace fuse and check harness for short circuit. Repair or replace as neces-
sary.

CHECK GROUND CIRCUIT FOR UNIFIED METER AND A/C AMP.

Turn ignition switch OFF.

Check continuity between unified meter and A/C amp. harness
connector M50 terminal 29 (B), 30 (B) and ground.

OK or NG

>> Replace unified meter and A/C amp.

>> Repair harness or connector.

Terminals

Ignition switch position

(+)

(-)

OFF

ACC

Auto amp.

connector

Terminal No.

(wire color)

M50

21 (Y/R)

Ground

Battery
voltage

M50

22 (G)

Approx. 0V

Battery
voltage

M50

35 (P/B)

Approx. 0V

Battery
voltage

M51

46 (W/L)

Approx. 0V

Battery
voltage

RJIA1984E

29, 30 – Ground

: Continuity should exist.

RJIA1985E

TROUBLE DIAGNOSIS

ATC-81

ATC

Revision; 2004 April

2003 Murano

LAN System Circuit

AJS000Z6

SYMPTOM: Mode door motor, intake door motor and/or air mix door motor(s) does not operate normally.

DIAGNOSTIC PROCEDURE FOR LAN CIRCUIT

CHECK POWER SUPPLY FOR UNIFIED METER AND A/C AMP.

Turn ignition switch ON.

Check voltage between unified meter and A/C amp. harness
connector M51 terminal 54 (L/W) and ground.

OK or NG

>> GO TO 2.

>> Replace unified meter and A/C amp.

CHECK SIGNAL FOR UNIFIED METER AND A/C AMP.

Confirm A/C LAN signal between unified meter and A/C amp. har-
ness connector M51 terminal 43 (L/B) and ground using an oscillo-
scope.

OK or NG

>> GO TO 3.

>> Replace unified meter and A/C amp.

RJIA1775E

54 – Ground

: Battery voltage

RJIA1986E

Terminals

Voltage

(+)

(-)

Auto amp.

connector

Terminal No.

(wire color)

M51

43 (L/B)

Ground

RJIA1987E

HAK0652D

ATC-82

TROUBLE DIAGNOSIS

Revision; 2004 April

2003 Murano

CHECK POWER SUPPLY FOR MOTOR

Check voltage between mode door motor harness connector M252
terminal 1 (L/W), driver side air mix door motor harness connector
M253 terminal 1 (L/W), passenger side air mix door motor harness
connector M254 terminal 1 (L/W), intake door motor harness con-
nector M255 terminal 1 (L/W) and ground.

OK or NG

>> GO TO 4.

>> Repair harness or connector.

CHECK SIGNAL FOR MOTOR

Confirm A/C LAN signal between mode door motor harness connec-
tor M252 terminal 3 (L/B), driver side air mix door motor harness
connector M253 terminal 3 (L/B), passenger side air mix door motor
harness connector M254 terminal 3 (L/B), intake door motor harness
connector M255 terminal 3 (L/B) and ground using an oscilloscope.

OK or NG

>> GO TO 5.

>> Repair harness or connector.

CHECK MOTOR GROUND CIRCUIT

Turn ignition switch OFF.

Disconnect door motor connector.

Check continuity between mode door motor harness connector
M252 terminal 2 (B), driver side air mix door motor harness con-
nector M253 terminal 2 (B), passenger side air mix door motor
harness connector M254 terminal 2 (B), intake door motor har-
ness connector M255 terminal 2 (B) and ground.

OK or NG

>> GO TO 6.

>> Repair harness or connector.

1 – Ground

: Battery voltage

RJIA1988E

Door motor

Terminals

Voltage

(+)

(-)

Con-

nector

Terminal

No.

(wire

color)

Mode

M252

3 (L/B)

Ground

Air mix
(Driver
side)

M253

3 (L/B)

Air mix
(Passen-
ger side)

M254

3 (L/B)

Intake

M255

3 (L/B)

RJIA1989E

HAK0652D

2 – Ground

: Continuity should exist.

RJIA1990E

TROUBLE DIAGNOSIS

ATC-83

ATC

Revision; 2004 April

2003 Murano

CHECK MOTOR OPERATION

Disconnect and reconnect the motor connector and confirm the motor operation.

OK or NG

>> (Return to operate normally.)

●

Poor contact in motor connector.

>> (Does not operate normally.)

●

GO TO 7.

CHECK MODE DOOR MOTOR OPERATION

Disconnect mode door motor and air mix door motor (driver side, passenger side) connector.

Reconnect mode door motor connector and confirm the mode door motor operation.

OK or NG

>> (Mode door motor operates normally.)

●

GO TO 8.

>> (Mode door motor does not operate normally.)

●

Repair mode door motor.

CHECK AIR MIX DOOR MOTOR OPERATION

Disconnect mode door motor connector.

Reconnect air mix door motor connector (driver side, passenger side) and confirm the air mix door motor
operation.

OK or NG

>> (Air mix door motor operates normally.)

●

GO TO 9.

>> (Air mix door motor does not operate normally.)

●

GO TO 10.

CHECK INTAKE DOOR MOTOR OPERATION

Disconnect air mix door motor connector (driver side, passenger side).

Reconnect intake door motor connector and confirm the intake door motor operation.

OK or NG

>> (Intake door motor operates normally.)

●

Repair unified meter and A/C amp.

>> (Intake door motor does not operate normally.)

●

Repair intake door motor.

10.

CHECK AIR MIX DOOR MOTOR OPERATION

Disconnect air mix door motor (driver side) connector.

Confirm the air mix door motor (passenger side) operation.

OK or NG

>> (Air mix door motor operates normally.)

●

Repair driver side air mix door motor.

>> (Air mix door motor does not operate normally.)

●

Repair passenger side air mix door motor.

TROUBLE DIAGNOSIS

ATC-85

ATC

Revision; 2004 April

2003 Murano

SYSTEM DESCRIPTION
Component Parts

Mode door control system components are:

●

Unified meter and A/C amp.

●

Mode door motor (LCU)

●

A/C LAN system (PBR built-in mode motor and air mix door motor)

●

In-vehicle sensor

●

Ambient sensor

●

Sunload sensor

●

Intake sensor

System Operation

The unified meter and A/C amp. receives data from each of the sensors. The unified meter and A/C amp.
sends air mix door, mode door and intake door opening angle data to the air mix door motor LCU, mode door
motor LCU and intake door motor LCU.
The air mix door motor, mode door motor and intake door motor read their respective signals according to the
address signal. Opening angle indication signals received from the unified meter and A/C amp. and each of
the motor position sensors are compared by the LCUs in each motor with the existing decision and opening
angles. Subsequently, HOT/COLD or DEFROST/VENT or FRESH/RECIRCULATION operation is selected.
The new selection data is returned to the unified meter and A/C amp.

RJIA1777E

TROUBLE DIAGNOSIS

ATC-87

ATC

Revision; 2004 April

2003 Murano

Air Mix Door Motor Circuit

AJS000Z8

SYMPTOM:

●

Discharge air temperature does not change.

●

Air mix door motor does not operate.

INSPECTION FLOW

ATC-69, "FUNCTION CONFIRMA-
TION PROCEDURE"

, see No. 4 to 6.

ATC-115, "Ambient Sensor Circuit"

ATC-118, "In-vehicle Sensor Cir-
cuit"

ATC-121, "Sunload Sensor Circuit"

ATC-89, "Air Mix Door Motor PBR
Circuit"

ATC-69, "FUNCTION CONFIRMA-
TION PROCEDURE"

, see No. 13.

ATC-81, "LAN System Circuit"

ATC-143, "AIR MIX DOOR
MOTOR"

*10

ATC-76, "Operational Check"

*11

ATC-57, "SYMPTOM TABLE"

*12

ATC-124, "Intake Sensor Circuit"

RJIA1780E

ATC-88

TROUBLE DIAGNOSIS

Revision; 2004 April

2003 Murano

SYSTEM DESCRIPTION
Component Parts

Air mix door control system components are:

●

Unified meter and A/C amp.

●

Air mix door motor (LCU)

●

A/C LAN system (PBR built-in mode motor and air mix door motor)

●

In-vehicle sensor

●

Ambient sensor

●

Sunload sensor

●

Intake sensor

System Operation

The unified meter and A/C amp. receives data from each of the sensors. The unified meter and A/C amp.
sends air mix door, mode door and intake door motor opening angle data to the air mix door motor LCU, mode
door motor LCU and intake door motor LCU.
The air mix door motor, mode door motor and intake door motor read their respective signals according to the
address signal. Opening angle indication signals received from the unified meter and A/C amp. and each of
the motor position sensors are compared by the LCUs in each motor with the existing decision and opening
angles. Subsequently, HOT/COLD or DEFROST/VENT or FRESH/RECIRCULATION operation is selected.
The new selection data is returned to the unified meter and A/C amp.

Air Mix Door Control Specification

RJIA1781E

RJIA1782E

TROUBLE DIAGNOSIS

ATC-89

ATC

Revision; 2004 April

2003 Murano

COMPONENT DESCRIPTION
Air Mix Door Motor

The air mix door motor is attached to the heater & cooling unit. It
rotates so that the air mix door is opened or closed to a position set
by the unified meter and A/C amp. Motor rotation is then conveyed
through a shaft and the air mix door position is then fed back to the
unified meter and A/C amp. by PBR built-in air mix door motor.

DIAGNOSTIC PROCEDURE FOR AIR MIX DOOR

Perform diagnostic procedure for

ATC-81, "DIAGNOSTIC PROCEDURE FOR LAN CIRCUIT"

Air Mix Door Motor PBR Circuit

AJS000Z9

SYMPTOM:

●

Discharge air temperature does not change.

●

PBR circuit is open or shorted.

DIAGNOSTIC PROCEDURE FOR AIR MIX DOOR PBR

Perform diagnostic procedure for

ATC-81, "DIAGNOSTIC PROCEDURE FOR LAN CIRCUIT"

RJIA1783E

RJIA1784E

Nissan Murano Z50 (2003 year). Manual - part 7